A person's eyes are a prominent and noticeable facial feature. Thus, any desirable or undesirable aesthetic features associated with the eyes may influence an individual's perception of herself or himself or the impression that the individual makes on others. Undesirable aesthetic features may include lines, wrinkles and discoloration of the skin. For example, some people may find periorbital dyschromia, sometimes referred to as dark circles or under-eye dark circles, to be aesthetically undesirable and/or they may associate the appearance of periorbital dyschromia with fatigue and/or age. It should come as no surprise then that throughout history a variety of ways to accentuate and/or beautify the eyes have been devised. A common approach to improve the appearance of periorbital dyschromia is to use a cosmetic composition such as a concealer or the like to hide the discoloration. Using make up to hide a perceived flaw may provide a temporary cosmetic benefit, but most conventional make up products require daily application and, in some instances, may even require reapplication throughout the day. Thus, a more permanent solution is desired to reduce and/or eliminate some of the undesirable aesthetic features commonly found around the eye.
As mentioned above, a particularly undesirable aesthetic eye feature is periorbital dyschromia. In an effort to find a solution to the problem of periorbital dyschromia, researchers have previously tried to identify its underlying causes. One theory suggests that periorbital dyschromia occurrence is based on the difference between the thickness of the skin in the periorbital region (i.e., the skin around the eye) and the thickness of the skin in other areas of the face such as the cheeks. It is known that the skin surrounding the eyes is typically thinner than other facial skin (e.g., on the order of 0.33 to 0.36 ram or 3 to 5 times thinner than the rest of the skin of the face). As a result, some conventional theories posit that the skin around the eyes may be easily dehydrated and particularly vulnerable to adverse impact of external factors such as heat, stress, tobacco, UV rays, and excessive facial expressions. According to these theories, the skin tissues around the eye area may undergo multiple variations throughout the day, such as vascularization, hydration and turgescence, which contributes to swelling/puffiness and/or the appearance of dark circles under the eyes. While the thinness of the skin in the periorbital region may play a role in the occurrence of periorbital dyschromia, it is not a suitable characteristic for distinguishing different types of periorbital dyschromia. This is because most people generally have thinner skin in the periorbital region compared to other areas of the face, yet not all people have the same type of periorbital dyschromia or, in sonic instances, any periorbital dyschromia at all. Thus, there remains a need to find suitable characteristics for distinguishing different types of dark circles.
Another theory attributes the occurrence of periorbital dyschromia to hyperpigmentation, or the overproduction of melanin in the skin under the eye. But recent studies have revealed that the cause of under-eye dark circles is more often the result of a combination of factors such as deep vascular congestion/superficial vascularity, hyperpigmentation, skin translucency, and structural shadowing, alone or in combination. The belief that a variety of factors are responsible for causing periorbital dyschromia has led to attempts to classify periorbital dyschromia into discrete types according to the different underlying factor(s) believed to be responsible for the discoloration. But these attempts have failed to provide a commercially viable method of classifying periorbital dyschromia or a system that is suitable for developing and marketing cosmetic products that target periorbital dyschromia. In some instances, there were too many classes of periorbital dyschromia, which requires a manufacturer to develop more cosmetic products or line ups and/or market a more complex treatment method. In some instances, the system used to classify the types of periorbital dyschromia may be too complex to allow consumer to self-diagnose, for example, at home or in a commercial environment such as a retail store.
Another theory suggests that chromophores such as melanin and hemoglobin present in the undereye region contribute to the occurrence of periorbital dyschromia. Melanin is a naturally produced pigment in the skin, and hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all humans. It is commonly believed that melanin and hemoglobin are primarily responsible for the skin tone of a person. Thus, some recent attempts to classify dark circles have included analyzing relatively small areas of skin on the lower eyelid with a device that correlates certain wavelengths of reflected light into measurements of melanin and/or hemoglobin present in the skin. While this approach may be suitable for providing an indication of the melanin and/or hemoglobin content of the particular area of skin analyzed, it has several drawbacks. For example, the amount of melanin and/or hemoglobin present in the skin or in the blood vessels in under-eye skin can vary based on a wide variety of environment and/or biological influences, which current analytical approaches do not consider. Additionally, current approaches to classifying dark circles based on melanin and hemoglobin levels may not take into account one or more of a variety of other factors believed to contribute to periorbital dyschromia, which are important to include in a robust classification method and/or system suitable for use in commerce. Previous attempts to analyze periorbital dyschromia based on melanin and hemoglobin measurements also focused on the skin of the lower eyelid. Since it is not uncommon for periorbital dyschromia to occur in the periorbital region above the eye and in portions of the undereye region, but not the entire undereye region, it is important to holistically analyze periorbital dyschromia in the periorbital region.
It is currently recognized that periorbital dyschromia is a multifactorial pathogenesis that is not well elucidated. Past attempts to classify periorbital dyschromia may have shown that there are different types of periorbital dyschronia, but they still have failed to provide a suitable method or system of classifying the different types. Further, there is a need for products, product line ups and/or treatment regimens that are particularly suited for treating different types of periorbital dyschromia. For example, some researchers may have recognized that there are different types of periorbital dyschromia, but they still propose treating different types of periorbital dyschromia with the same composition or material. Other researchers have suggested that a “one size fits all” approach to treating periorbital dyschromia may not be suitable, due to the numerous and not well understood differences in the underlying causes of periorbital dyschromia, but they do not proffer a suitable alternative. Thus, there remains a need for a suitable method and system of classifying periorbital dyschromia, and, in particular, one that is more suitable for commercial use. Otherwise, manufacturers may find it too difficult and/or unpredictable to design and market products and treatment regimens for the diverse array of consumers who typically use their products. Similarly, in some instances, it may be desirable for consumers to self-diagnose, and thus it would be desirable for the method and system to be user friendly, for example, in a commercial setting such as a retail store.